The invention relates to a method for the closed loop control of the instant of ignition utilizing peak combustion chamber pressure detection relative to the occurrence of top dead center in the combustion chamber.
In internal combustion engines functioning with externally supplied ignition, it is known to control the instant of ignition in closed-loop fashion in accordance with the occurrence of the peak pressure relative to the occurrence of top dead center during the combustion process. An optimal set-point value representative of the angular crankshaft position at which the peak pressure is supposed to occur in the combustion chamber is generated, and the instant of ignition is appropriately corrected when there is a deviation from this set-point value. (See Powell; "Closed Loop Control of Spark Timing", Automobile Engine Control Symposium, April, 1976).
The combustion chamber pressure is detected by a transducer. The transducers for detecting the combustion chamber pressure are, however, problematical in terms of their manufacture, functional reliability, and ease of installation in the combustion chamber of an internal combustion engine.